How to Install a Power Inverter in a Semi-Truck

Once you’re done you’ll be able to enjoy all the benefits and run almost any home appliance including TVs, microwaves, laptops, heaters, fans, and much more.

Before you go ahead with the installation just check your inverter is correct for your needs. Keep reading to find a selection of points to consider plus take a look at my in-depth guide to the Best Power Inverters for Semi-Trucks.

If you’re ready to install an inverter in a semi-truck then let’s get started.

The following information below is an overall guide. Each inverter and vehicle is different so if you are not sure at any point then ask a professional.

Installing an Inverter in a Semi-Truck (Step-by-Step)

Below is a step-by-step process to easily connect an inverter in a semi-truck. Before you begin, make sure you’ve got everything you need. Your inverter will usually arrive with the correct cables, lugs, connections, and mounting plate.

What You’ll Need:

Inverter
Battery
Cables
Mounting System (Screws, Velcro, etc)
Wire Stripers*
Lugs*
Crimping Tool*
In-line Fuse (optional)

*Not necessary if your inverter comes ready with the correct cables.

Check this video walk-through for a visual guide:

1. Battery Choice

The first thing to decide is which battery you’re connecting to your inverter. Most trucks should already have deep-cycle leisure batteries which are separate from your starter battery. This means you won’t risk depleting your starter battery, plus you can use the inverter without running the engine. Often semi-trucks include extra space for additional batteries.

2. Mounting Position

Once the battery is located, you need to find a place to mount your inverter. You want to use a well-ventilated dry area near the battery, keeping the cables short between the inverter and battery will help to maintain voltage. You should not mount your inverter inside the engine bay, it should be placed inside the vehicle.

Consider what items and where you will be running them to allow easy access for your electronics.

Once in position, you should securely mount your inverter. It should have built-in mourning plates to screw into place.

3. Prepare and Run Cables

Now it’s time to prepare your cables. Inverters will arrive with preinstalled cables that are hooked up to the positive and negative input terminals. These cables should have handy O-ring lugs to hook up to the battery.

If the cables are not ready to use then you will need to add the lugs yourself. For the correct AWG cable check the user manual or product information. To add lugs you must strip the ends to expose the copper wire. Then simply slide the lugs on and crimp snug and tight. Finish this with electrical tape.

Here’s a useful video to show you how

3.1 Consider in-line fuse

One consideration in your cables is adding an in-line fuse. Most modern inverters come with built-in fuses. This protects the inverter and the connected appliances. It will not protect the cables between the battery and the inverter. It is best to add an in-line fuse to the positive battery block/cable. Then if the wires become damaged or exposed the fuse will protect your circuit. This is not essential but is recommended with permanent setups.

For an inline fuse, you must split the positive cable within 7 inches of the battery. Next, strip the cable and add lugs (similar to the instructions above) before securing each end in the in-line fuse.

With your cables prepared you can run them from the inverter to the battery. Often you need to drill holes from the cab to the battery bay. Check where you are drilling through to avoid disaster. If you don’t own the semi-truck then discuss it with the owner before carrying out the work.

4 Connect Positive

Make sure you are wearing safety glasses and gloves before starting your connections.

Everything is ready to hook your inverter to your battery. Connect the red cable to the red battery terminal.

5 Connect Negative

Now hook up the black cable to the black battery terminal. That’s negative to negative. Ensure you get a good snug connection between the lug and the metal terminal. Be careful as the connection might spark.

6. Add Ground

When connecting to an exterior battery you will need to run a ground wire. Find the small outlet on the back of the inverter marked ground. Run a wire from here to the metal frame of your vehicle. Some inverters don’t require this as the metal casing acts on its behalf.

If you’re connecting to a vehicle starter battery the negative battery terminal should already be grounded.

7. Test

Let’s make sure everything works correctly.

Without any appliances attached, power on your inverter to check it is working. A green LED light should appear, plus any LCD screens should show voltage levels.

Any errors should be fixed immediately, a red light or alarm might occur on your inverter. Adding to this, listen out for any sounds like squealing. Common issues include poor connections, reverse polarity (wired backward), overvoltage, or undervoltage. Any faults stop your inverter from working as it protects itself from damage.

Tips for Using a Semi-Truck Power Inverter

Now you know how to install an inverter in a semi-truck, let’s go through some helpful tips for the best usage.

Switch Off When Not in Use

My first tip is to switch off your inverter when it’s not in use. This is because an inverter still draws power even when no load is connected. They need electricity to run their internal systems such as safety monitoring, cooling, lights, and screens. If you leave an inverter turned on when not in use it slowly depletes your battery energy.

This is frustrating if you don’t have access to easy recharging solutions like a split relay, hookups, or solar panels.

Keep Well Ventilated

Inverters need airflow to keep cooling. This is even more important for large inverters. High amounts of power create heat that must dissipate from your equipment. Vents and fans require cool air for this operation. Don’t put your inverter in a sealed confined area, plus ensure vents are not covered. If your inverter starts to overheat it will shut down to protect itself.

Avoid Liquid

Inverters are not waterproof so don’t get them wet. Avoid mounting them where there is a risk of rain or spillage. When an inverter gets wet then turn it off and let it thoroughly dry out.

Maintenance

Power inverters don’t need too much maintenance. After the initial installation in your semi-truck, you can leave it to run. You should still keep it clean by removing any dust or dirt. You might see a particular build-up near outlets and cooling fans. Remove any dirt or obstructions to your cooling fans for efficient performance.